From 1622ed7d0743201293094162c26019d2573ecacb Mon Sep 17 00:00:00 2001 From: Baokun Li Date: Fri, 21 Jan 2022 22:13:48 -0800 Subject: [PATCH] sysctl: returns -EINVAL when a negative value is passed to proc_doulongvec_minmax When we pass a negative value to the proc_doulongvec_minmax() function, the function returns 0, but the corresponding interface value does not change. we can easily reproduce this problem with the following commands: cd /proc/sys/fs/epoll echo -1 > max_user_watches; echo $?; cat max_user_watches This function requires a non-negative number to be passed in, so when a negative number is passed in, -EINVAL is returned. Link: https://lkml.kernel.org/r/20211220092627.3744624-1-libaokun1@huawei.com Signed-off-by: Baokun Li Reported-by: Hulk Robot Acked-by: Luis Chamberlain Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index e92e8d2..5ae443b 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1145,10 +1145,11 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, err = proc_get_long(&p, &left, &val, &neg, proc_wspace_sep, sizeof(proc_wspace_sep), NULL); - if (err) + if (err || neg) { + err = -EINVAL; break; - if (neg) - continue; + } + val = convmul * val / convdiv; if ((min && val < *min) || (max && val > *max)) { err = -EINVAL; -- 2.7.4